Validation of the Xstrahl Small Animal Radiation Research Platform using in vivo and in vitro studies.
Since conception Xstrahl has partnered with the John Hoskins University to validate and develop the X-ray irradiator systems. In addition Xstrahl’s user group is active in collaborating ideas and solutions to help advance the systems and their aplications.
The SARRP allows researchers to obtain a 3D CBCT image, identify the desired target, and treat within 0.2mm of isocenter accuracy. Due to the complexity of these processes, our team of skilled engineers and physicists validate all these aspects in house.
As the machine has developed over the years we have, and continue to collaborate with users to further validate the machine.
Irradiation cabinets have been traditionally used for both in vitro and in vivo treatments. The SARRP offers the user an advantage with in vivo treatments by mimicking the geometry and movements of Human Radiation Therapy treatment. Research usually begins with an in vitro component. This allows the user to be able to visualize and quantify results. With the advancement in irradiators we can now use imaging to track tumors and quantify the results.
Another key topic between in vitro and in vivo studies is the value of the tumor micronenvironment. If you use cells, subcutaneous human derived tumors, orthotopic human derived tumors or spontaneous mouse derived tumors, you can create many different microenvironments. This relates directly to the blood flow, vasculature, hypoxia and growth of a tumor.
Hedgehog pathway has been implicated in tumor recurrence. Inhibitors of this pathway have shown radioresistance (hepatocellular) and radiosensitivity (esophageal) in vitro. This study on non-small cell lung cancer showed no significant radioresistance in vitro. In vivo (xenograft and orthotopic models) both showed great radiosensitivity verified by CBCT on SARRP.
The SARRP System was designed by a team of Physicists and Engineers at Johns Hopkins University lead by Dr. John Wong. Several studies were performed to prove the accuracy of the system.
All of the parts of the system add up to the overall accuracy so each part is individually tested and proven to have a small accuracy. The articles below validate the accuracy and viability of the SARRP.
These researchers attempted to use SARRP to mimic a clinical treatment. They used a head and neck human tumor in a nude mouse model. They imaged these mice on a PET and created a plan based on the area of interest and a boost to the area of high FDG uptake. This PET image was fused with SARRP CT image while the mouse was anesthetized. 10Gy was given using a 15mm collimator to the whole tumor. The boost was treated with 10Gy using a non-coplanar dynamic arc with the 5mm collimator. The researchers found that a PET/CT with the SARRP can allow for pre-clinical validation of PET image-guided dose escalation IMRT treatments.